Navigation Links
Ion gradient


An ion gradient is a concentration gradient of ions, it can be called an electrochemical potential gradient of ions across membranes. Ionophores are important for ion gradients. The chemiosmotic potential is used as energy storage, chemiosmotic coupling is one of several ways a thermodynamically unfavorable reaction can be driven by a thermodynamically favorable one, I.E by letting the ions diffuse through the high concentration side to the low concentration side through transmembrane proteins which can use them as energy. Several different types of ion gradients exists in biological systems, the most common one is the proton gradient. Transmembrane ATPases or transmembrane proteins with ATPase domains are often used for making and utilizing ion gradients. The enzyme Na+/K+ ATPase use ATP to make a sodium ion gradient and a potassium ion gradient.

Proton gradients

The proton gradient can be used as an intermediate energy storage for heat production and flagellar rotation . Additionally it is an interconvertible form of energy in active transport, electron potential generation, NADPH synthesis and ATP synthesis/hydrolysis.

Some archaea, most notably halobacteria, make proton gradients by pumping in protons from the environment with the help of the solar driven enzyme bacteriorhodopsin, here it is used for driving the molecular motor enzyme ATP synthase to make the necessary conformational changes required to synthesize ATP.

Proton gradients are also be made by bacteria by running ATP synthase in reverse, this is used to drive flagellas.

The F1FO ATP synthase is a reversible enzyme. Large enough quantities of ATP cause it to create a transmembrane proton gradient, this is used by fermenting bacteria which do not have an electron transport chain, and hydrolyze ATP to make a proton gradient, which they use for flagella and transport of nutrients into the cell.

In respiring bacteria under physiological conditions, ATP synthase generally runs in the opposite direction, creating ATP while using the protonmotive force created by the electron transport chain as a source of energy. The overall process of creating energy in this fashion is termed oxidative phosphorylation. Same process takes place in mitochondria, were ATP synthase is located in the inner mitochondrial membrane (so that F1-part sticks into mitochondrial matrix, were ATP synthesis takes place).

See also


'"/>


(Date:8/12/2015)... Aug. 12, 2015  Synaptics Inc. (NASDAQ: ... solutions, today announced that four of its fingerprint ... have officially been named FIDO Certified™ by the ... the certification, Synaptics, Natural ID™ fingerprint solutions are ... Framework (UAF) standard and are interoperable among other ...
(Date:8/6/2015)... TELTOW, Germany , August 6, 2015 ... SensoMotoric Instruments (SMI) shows the world,s first ... based on Epson,s Moverio BT-200 see-through head mounted ... this new solution, unprecedented quality and efficiency is brought ... context-sensitive displays. For the first time, professionals and researchers ...
(Date:8/4/2015)... , Aug. 04, 2015 ... http://www.researchandmarkets.com/research/nvh7k2/digital_forensics ) has announced the addition of ... (Hardware, Software, and Service), Sub-Segment (Computer Forensics, ... Forensics), Tool Types, Service, Vertical and Region ... to their offering. By Component ...
Breaking Biology News(10 mins):Synaptics Announces FIDO Certification of Natural ID Fingerprint Solutions 2Synaptics Announces FIDO Certification of Natural ID Fingerprint Solutions 3SMI Shows First Eye Tracking Upgrade for Augmented Reality Glasses 2SMI Shows First Eye Tracking Upgrade for Augmented Reality Glasses 3Digital Forensics Market - The Market Represents a Compound Annual Growth Rate (CAGR) of 11.3% From 2015 to 2020 2
... University professor is helping students improve their confidence ... learning. Candice Shoemaker, professor of horticulture, has ... and self-efficacy. Self-efficacy involves student confidence in understanding ... learning and achievement. Shoemaker,s published research appeared in ...
... University of Guam ecologist Thomas Marler recently mobilized efforts ... eruption of Mount Pinatubo, Philippines. "My interest was sparked ... was so powerful it changed global climate, yet after ... ecosystem had not been studied," said Marler. ...
... of all women scientists and one-quarter of male scientists at ... them from having as many children as they had wanted, ... Methodist University (SMU). The study, "Scientists Want More ... and Anne Lincoln of SMU and appears in the current ...
Cached Biology News:Finding their way: Study shows connection between academic direction and student learning 2Finding their way: Study shows connection between academic direction and student learning 3Guam researcher studies Mount Pinatubo ecosystem recovery 2Many top US scientists wish they had more children 2Many top US scientists wish they had more children 3
Other biology definitionOther Tags